This invention relates to apparatus and methods for broadcasting and receiving television signals. More particularly, this invention relates to an apparatus and method for providing local originating channels along with direct broadcast satellite television channels transmitted from a satellite.
Television signals may be received from a satellite in geosynchronous orbit in which it is stationary with respect to a geographic receiving area. Typically, the television signals are transmitted from a terrestrial transmitter to the satellite and then retransmitted from the satellite so that the signals can be received by terrestrial receivers within the geographic receiving area, that is, within a line of sight of the satellite.
Direct broadcast satellite service ("DBS") refers to satellite transmission of television signals directly for use by individual households or subscribers having the proper signal receiving equipment. The U.S. Federal Communications Commission has dedicated the electromagnetic spectrum from 12.2 Giga-Hertz to 12.7 Giga-Hertz for DBS broadcasting. Sixteen signal carriers are located within the DBS spectrum, each carrier carrying several individual television channels. Depending upon the compression technology applied to these signals, literally hundreds of separate channels may be available through DBS. A great benefit of the DBS system as opposed to prior satellite systems is that only a small dish-type antenna is required to receive the DBS signals and the alignment of the receiving dish is not critical. Also, the DBS system will provide high quality reception at any point in the geographic receiving area of a satellite without the expense of land transmission lines such as those required for cable television.
The DBS system requires that a subscriber purchase or rent both a special DBS signal processing unit or receiver and a DBS satellite signal receiving antenna. The receiver and antenna are usually provided as one assembly having an outdoor unit and an indoor unit. The special DBS receiver receives all sixteen carriers and includes channel selecting logic for selecting a desired program channel from the received carriers. To produce a single channel program output to a television set, the DBS receiver channel selecting logic selects one of the sixteen carriers and then demodulates and decodes the encoded signals. Finally the receiver converts the desired channel signal from digital form to analog form to provide the channel input to the television set.
A major problem with the DBS system involves local originating programming or television channels. Since a single DBS satellite transmits to substantially an entire continent, DBS can effectively only provide national or at most regional programming. There is simply not enough room in the DBS spectrum for all local originating programming to be transmitted through the satellite for selection by individual subscribers. Rather, DBS subscribers must obtain local originating programming from other sources such as local broadcast stations, cable, or local wireless sources. These separate sources all require separate receiving equipment. Furthermore, the advantages of DBS are less attractive to potential subscribers because the subscribers must also use a separate system, cable for example, in order to obtain local programming. In fact, there has been great concern that the absence of local programming with DBS may make the DBS system commercially unviable.